Joining method and joining structure as well as form for concrete products

ABSTRACT

The present invention relates to a joining method and a joining structure as well as a form for concrete products. A protruding portion provided at the front end of a seal member of elastic material attached to one concrete product is inserted through an opening formed in a joining face of the other concrete product into an attachment hole of enlarged diameter provided at a depth of the opening, while bringing a closing press contact portion of the seal member into press contact with inner surfaces of the opening to achieve an airtight condition inside the attachment hole, followed by filling grout into a space defined between inner surfaces of the attachment hole and the protruding portion and setting the grout there to join the concrete products together.

FIELD OF THE INVENTION

The present invention relates to a joining method and a joiningstructure as well as a form for concrete products for easily andreliably connecting together concrete products including, for example,construction materials such as concrete box culverts, side channels andU-shaped channels, and building materials such as outside wall panelsand inside wall panels.

BACKGROUND OF THE INVENTION

A method of joining together at the laying side concrete productsincluding construction materials such as box culverts, side channels andU-shaped channels must conventionally meet the requirements, (a)providing a rigid connectivity ensuring a structural integration of theconcrete products; (b) providing a flexibility at the joining points ofthe concrete products in order to ensure earthquake resistantproperties; and (c) providing water cutoff properties for preventing anyleakage of liquid.

However, there have hitherto existed no joining methods that satisfy allthe requirements (a) to (c) mentioned above.

Joining methods that merely provide the rigid connectivity of (a) aboveinclude the method as shown in FIG. 12, in which opposed joining faces1, 1 of concrete products A, B are adhered to each other with anadhesive S of cement mortar, synthetic resin or the like.

Another joining method is illustrated in FIG. 13, in which joining faces1, 1 of concrete products A, B are provided with respective, opposedprojecting steel plates 50, 50, which are welded together to join theconcrete products.

A third joining method is illustrated in FIG. 14, in which anappropriate number of steel rods 51 are provided between joining faces1, 1 of concrete products A, B and at one end linked to one concreteproduct A and at the other end linked to the other concrete product B tojoin them together.

Further, a fourth joining method is illustrated in FIG. 15, in whichsteel rods 52, 52, a sleeve 53 and a filler 54 are used to connect theconcrete products A, B together.

The conventional adhesive-using method as shown in FIG. 12, however,entails a deficiency that the joining points, when the concrete productsA, B are joined together, are subject to stresses and thus to fracture.

The conventional method as shown in FIG. 13, in which the opposed steelplates 50, 50 projecting at the joining faces 1, 1 of the concreteproducts A, B are welded, entails a deficiency that it requires skilland lots of time and labor for the welding operation, resulting in aninefficient joining operation as well as an increase in constructioncosts. In addition, the steel plates 50, 50 are susceptible tocorrosion.

The conventional method as shown in FIG. 14 which uses steel rods 51 tojoin the concrete products A, B entails a deficiency that it involvesthe selection of the number of steel rods 51 to use and the positionswhere to provide the steel rods 51 as well as the thickness of the steelrods 51 to use from the point of view of design in consideration of therequired strength and structure, resulting in a complicated designing.Likewise, with the conventional method as shown in FIG. 15, theselection of steel rods 52 and their assembly to the sleeve 53 anddesign have been complicated. In addition, both the joining methods haverequired lots of time and labor, leading to inefficiency in joining theconcrete products A, B and an increase in construction costs, materialcosts and production costs.

Further, an O-ring, a rubber packing or the like has been used toprevent leakage of water between the concrete products A, B joined.

The present invention has been conceived in order to overcome the abovedeficiencies, and an object of the present invention is to provide ajoining method and a joining structure as well as a form for concreteproducts, which enable an unskilled person to join concrete productstogether with a simple handling operation, which impart a structuralfirmness and a sufficient rigid connectivity as well as excellentearthquake resistant properties and water cutoff properties, and whichare easy to produce and design and capable of reducing constructioncosts and material costs.

DISCLOSURE OF THE INVENTION

In order to attain the above object, a first invention of the presentinvention provides a joining method for concrete products comprising thesteps of: inserting a protruding portion at a front end of a seal memberof elastic material attached at a rear end to a joining face of oneconcrete product through an opening formed in a joining face of theother concrete product opposed to the one concrete product into anattachment hole of enlarged diameter provided at a depth of the opening;bringing a closing press contact portion provided rearwardly of theprotruding portion into press contact with inner surfaces of the openingto keep an interior of the attachment hole airtight; and filling groutinto a space defined between inner surfaces of the attachment hole andthe protruding portion inserted into the attachment hole and setting thegrout there to join the one and the other concrete products together bymeans of the seal member.

A second invention provides a joining method for concrete products, oneof which includes a first attachment surface formed at a desired angleon a joining face thereof, and the other of which includes a secondattachment surface formed at a desired angle on a joining face thereof,an opening formed in the second attachment surface and an attachmenthole of enlarged diameter formed at a depth of the opening, the methodcomprising the steps of: inserting a protruding portion provided at afront end of a seal member of elastic material, which is at a rear endthereof attached to the first attachment surface, through the openingformed in the second attachment surface into the attachment hole;bringing a closing press contact portion provided rearwardly of theprotruding portion into press contact with inner surfaces of the openingto keep an interior of the attachment hole airtight; and filling groutinto a space defined between inner surfaces of the attachment hole andthe protruding portion inserted into the attachment hole and setting thegrout there to join the one and the other concrete products together bymeans of the seal member.

A third invention provides the joining method according to the first orsecond invention, wherein the step of filling grout comprises fillingthe grout through and into the space which serves as an introductionpassage for the grout, and which is defined between the inner surfacesof the attachment hole and the protruding portion provided at the frontend of the seal member inserted into the attachment hole.

A fourth invention provides the joining method according to the first orsecond invention, wherein the step of filling grout comprises fillingthe grout through an introduction passage in communication with theattachment hole, which is provided internally of the seal member whoseprotruding portion at the front end is inserted into the attachmenthole, into the space defined between the inner surfaces of theattachment hole and the protruding portion inserted into the attachmenthole.

A fifth invention provides the joining method according to the secondinvention, wherein the step of inserting comprises inserting theprotruding portion provided at the front end of the seal member from adirection substantially perpendicular to a joining direction of theconcrete products into the attachment hole, and the step of fillinggrout comprises filling the grout, after completion of the insertion ofthe protruding portion into the attachment hole, from a directionsubstantially perpendicular to the joining direction of the concreteproducts into the space defined between the inner surfaces of theattachment hole and the protruding portion.

A sixth invention provides the joining method according to any one ofthe second to fifth inventions, wherein the seal member with theprotruding portion formed at the front end which is inserted and fixedin the attachment hole provided at the depth of the opening formed inthe attachment surface is provided at an outer side of the opposedconcrete products.

A seventh invention provides the joining method according to any one ofthe second to fifth inventions, wherein the seal member with theprotruding portion formed at the front end which is inserted and fixedin the attachment hole provided at the depth of the opening formed inthe attachment surface is provided at an inner side of the opposedconcrete products.

An eighth invention provides a joining structure for concrete productscomprising: one and the other opposed concrete products each with ajoining face; a seal member of elastic material attached to the joiningface of the one concrete product and including a protruding portion at afront end thereof and a closing press contact portion providedrearwardly of the protruding portion; and an opening formed in thejoining face of the other concrete product and an attachment hole ofenlarged diameter provided at a depth of said opening, wherein theprotruding portion of the seal member is inserted through the openinginto the attachment hole, the closing press contact portion is broughtinto press contact with inner surfaces of the opening, and grout isfilled into a space defined between inner surfaces of the attachmenthole and the protruding portion inserted into the attachment hole andset to join the one and the other concrete products together by means ofthe seal member.

A ninth invention provides a joining structure for concrete productscomprising: one and the other opposed concrete products each with ajoining face, the one concrete product including a first attachmentsurface formed at a desired angle on the joining face thereof, the otherconcrete product including a second attachment surface formed at adesired angle on the joining face thereof, an opening formed in atapered manner in section in the second attachment surface, and anattachment hole of enlarged diameter provided at a depth of andcontinuous to the opening; and a seal member of elastic materialattached to the first attachment surface of the one concrete product andincluding a protruding portion at a front end thereof which is larger indiameter than a minimum dimension between inner surfaces of the openingand insertable into the attachment hole, and a closing press contactportion formed rearwardly of the protruding portion which elasticallycomes into press contact with the inner surfaces of the opening, whereinthe protruding portion of the seal member is inserted into theattachment hole, and grout is then filled into a space defined betweeninner surfaces of the attachment hole and the seal member inserted intothe attachment hole and is set to join the one and the other concreteproducts together by means of the seal member.

A tenth invention provides the joining structure according to the ninthinvention, wherein the one and the other concrete products each has theopening formed in the respective attachment surface and the attachmenthole at the depth of the respective opening, and the seal member is atopposite ends provided with the closing press contact portion and theprotruding portion, wherein after positioning the protruding portionsand the closing press contact portions in the respective attachmentholes and the respective openings continuous to the attachment holes,grout is filled into spaces defined between the inner surfaces of theattachment holes and the protruding portions inserted into theattachment holes and is set to join the one and the other concreteproducts together by means of the seal member.

An eleventh invention provides the joining structure according to theeighth or ninth invention, wherein the opening is tapered toward theattachment hole of enlarged diameter provided at the depth of theopening, and a narrow part is formed at a boundary between theattachment hole and the opening.

A twelfth invention provides the joining structure according to theeighth or ninth invention, wherein the closing press contact portion isformed on a tapered inclined portion of the seal member which is of suchheight as to be capable of comming into press contact with the innersurfaces of the opening.

A thirteenth invention provides the joining structure according to anyone of the eighth to tenth inventions, wherein the closing press contactportion has locking tongues formed in a serrated manner on at least oneof upper and lower surfaces thereof, which tongues are capable of cominginto press contact with the inner surfaces of the opening.

A fourteenth invention provides a form for concrete products comprisinga hole-forming male loose piece of elastic material such as rubber orsynthetic resin set at a desired position on an inner surface of theform.

A fifteenth invention provides the form according to the fourteenthinvention, wherein the loose piece of elastic material comprises atapered base portion with an attachment seat formed at a rear endthereof, and a male protruding portion of enlarged diameter provided ata front end of the base portion.

A sixteenth invention provides the form according to the fifteenthinvention, wherein the male protruding portion has a hollow portionformed therein for permitting expansion or contraction of the maleprotruding portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged partial perspective view of a first embodiment ofa joining method and a joining structure for concrete products inaccordance with the present invention;

FIG. 2 is a perspective view of concrete products in the form of boxculverts about to be connected;

FIG. 3 is an enlarged section of the concrete products joined togetherby means of a seal member;

FIG. 4 is an enlarged section of an example of a form for concreteproducts in accordance with the present invention;

FIG. 5 is an enlarged section of another example of a form for concreteproducts in accordance with the present invention;

FIG. 6 is a perspective view of concrete products in the form of boxculverts in accordance with a second embodiment of the presentinvention, about to be connected;

FIG. 7 is an enlarged section of the box culverts joined together bymeans of a seal member;

FIG. 8 is an enlarged partial section of a third embodiment of a joiningmethod and a joining structure for concrete products in accordance withthe present invention;

FIG. 9 is a perspective view of a fourth embodiment of the presentinvention showing a joining method and a joining structure for concreteproducts in accordance with the present invention applied to U-shapedchannels;

FIG. 10 is an enlarged section of the above concrete products connectedtogether;

FIG. 11 is an enlarged section of a fifth embodiment of the presentinvention showing a concrete product being connected;

FIG. 12 is a section of a first conventional joining method in whichconcrete products are joined together with an adhesive;

FIG. 13 is a section showing a second conventional joining method inwhich steel plates provided projecting on the joining faces of concreteproducts are welded to join the concrete products together;

FIG. 14 is a section showing a third conventional joining method inwhich steel rods are connected to both the concrete products to bejoined together; and

FIG. 15 is a section showing a fourth joining method in which a sleeveand steel rods are used to join concrete products together.

BEST MODE TO CARRY OUT THE INVENTION

An exemplary embodiment of the present invention will now be describedwith reference to the accompanying drawings.

Referring to FIGS. 1 to 5, a joining method and a joining structure aswell as a form for concrete products according to one embodiment of thepresent invention will be described in detail.

Referring to FIGS. 1 and 2, A and B denote concrete products to bejoined together which, in this embodiment, take the form of box culvertsb, b as shown in FIG. 2. These products A, B have opposed joining faces1, 1 which come into contact with each other at the time of juncture.

At least one of the concrete products A and B to be joined togetherincludes an opening 2a provided substantially circular in front view inthe joining face 1. The opening 2a leads to an attachment hole 2 havingas shown substantially a circular section of an enlarged diameter, whichis for receipt therein of a protruding portion 3a formed at the frontend of a seal member 3.

The opening 2a is tapered in section toward the enlarged diameterattachment hole 2 provided at the inner part and has a narrow portion orneck 2b at the boundary between the attachment hole 2 and the opening2a. Denoted 1 is a minimum dimension between inner walls of the opening2a.

To form the attachment hole 2 in the concrete product A, B, ahole-forming male elastic loose piece 4 made of elastic material such asrubber or synthetic resin, for example, is attached at a desiredposition on an inner surface of a concrete form 5 as shown in FIG. 4.The elastic loose piece 4 consists of a tapered base portion 4a with anattachment seat 4a₁ at the rear end and a male protruding portion 4b ofan enlarged diameter formed at the front end of the base portion 4a.

To form a concrete product with the attachment hole 2, concrete isfilled into the form 5, set and thereafter released, at which time theelastic loose piece 4 is elastically scaled down to be easily pulled outfrom the concrete product attachment hole 2 through the neck 2b toprovide the attachment hole 2 and the tapered opening 2a continuousthereto.

With the structure as shown in FIG. 5 in which the male protrudingportion 4b is internally provided with a hollow portion 4b₁ which scalesup or down on release or application of a pressing force, the maleprotruding portion 4b can, at the time of releasing the concreteproduct, be more easily pulled out of the attachment hole 2 through theneck 2b than with the one as shown in FIG. 4.

The seal member 3 is formed of elastic material and is at the rear end3b attached to the other concrete product B and has, for example, theprotruding portion 3a at the front end.

In this embodiment, the seal member 3 is at both the ends provided withthe swelled protruding portions 3a, 3a each having substantially asemi-circular section as shown. The elastic materials for forming theseal member 3 include, for example, not only rubber or synthetic resinbut also braided inorganic fibers such as glass fibers, carbon fibers.Denoted 3c are closing press contact portions located rearwardly of theprotruding portions 3a, which closing press contact portions 3c areformed on tapered inclined portions 3c₁, 3c₁, of such a height h as tocome into press contact with inner surfaces of the openings 2a when theseal member 3 is inserted into the opening 2a. When the closing presscontact portion 3c is thus brought into contact with inner surfaces ofthe opening 2a, an airtight condition is achieved inside the attachmenthole 2 and the opening 2a.

Denoted K is a space defined between inner surfaces of the attachmenthole 2 and the protruding portion 3a of the seal member 3 inserted intothe attachment hole 2. When grout 6 has been filled into the space K andset, the concrete products A and B are interconnected by means of theseal member 3.

As the grout 6, for example a non-shrinkable cement mortar is preferablyused, but liquid rubber, sythetic resin or the like is also usable. Thegrout 6 is filled from outside the concrete product A into the space Kwhich serves as an introduction passage 7 defined between the protrudingportion 3a provided at the front end of the seal member 3 and innersurfaces of the attachment hole 2, and is set. Denoted 7a is anintroduction port leading to the introduction passage 7. The grout 6 isfilled through the introduction port 7a into the space K in the concreteproduct A, B by means of a filling machine.

X represents a direction in which the concrete products A, B are joinedtogether, Y represents a direction horizontally intersecting the joiningdirection X, and Z represents a direction vertically intersecting thejoining direction X.

The joining structure for concrete products according to one embodimentof the present invention is constructed as described above. Descriptionwill now be made of a method of joining the concrete products A and B,along with its operative function in the sequence of steps.

To join together at a laying site the concrete products A, B in the formof box culverts b, b in the present embodiment, the protruding portion3a at the front end of the seal member 3--which is at the rear end 3battached to the joining face 1 of one concrete product B--is firstinserted in the joining direction X through the opening 2a providedsubstantialy circular in front view in the joining face 1 of the otherconcrete product A into the attachment hole 2 (see FIGS. 1 and 2). Theprotruding portion 3a provided at the front end of the seal member 3 isthus positioned inside the substantially circular in section attachmenthole 2, at which time the tapered closing press contact portion 3clocated rearwardly of the protruding portion 3a comes into contact withinner surfaces of the opening 2a to keep the interior of the attachmenthole 2 airtight.

Further, when the protruding portion 3a is positioned inside theattachment hole 2, the space K is defined around the periphery of theprotruding portion 3a in the attachment hole 2 to form the introductionpassage 7 continuous to the interior of the opening 2a.

The grout 6 is then filled through the introduction port 7a and theintroduction passage 7 into the space K defined between inner surfacesof the attachment hole 2 and the protruding portion 3a inserted into theattachment hole 2, and is set. At that time, the grout 6 is filled bymeans of a filling machine (see FIG. 3). As the grout 6, anon-shrinkable cement mortar is preferably used, but liquid rubber orsynthetic resin is also usable.

Then, when the grout 6 is filled into the space K and set, the swelledprotruding portion 3a of the elastic material-made seal member 3positioned inside the substantially circular in section attachment hole2 formed in the concrete product A is fixed in a watertight manner inthe the attachment hole 2 due to the setting of the grout 6.

At that time, due to the fact that the protruding portion 3a at thefront end of the seal member 3 positioned inside the substantiallycircular in section attachment hole 2 has substantially a semi-circularsection, and that the narrow neck 2b is formed at the boundary betweenthe attachment hole 2 and the tapered opening 2a continuous to theattachment hole 2, the protruding portion 3a is firmly fixed inside theattachment hole 2 due to the grout 6 filled in the space K. The neck 2bprevents the protruding portion 3a from coming out of the attachmenthole 2, leading to a sufficient rigid connectivity.

Thus, the end of the seal member 3 is securely and structurally firmlyattached to the concrete product A, so that the concrete products A, Bin the form of box culverts are joined together by means of the elasticmaterial-made seal member 3.

Although in the illustrated example the attachment hole 2 is shownsubstantially circular in section, the shape is not limited thereto, andthe attachment hole 2 may have a triangular, rectangular, pentagonal orhexagonal section. Likewise, the protruding portion 3a inserted into theattachment hole 2 is shown substantially semi-circular in section todefine therearound in the attachment hole 2 the space k serving as theintroduction passage 7, but the shape is not limited thereto and may besubstantially a circular, triangular, rectangular, pentagonal orhexagonal section.

In short, it suffices if the protruding portion 3a is swelled relativeto the main portion of the seal member 3 and is of such a desired shapeas to define the space K, when inserted into the attachment hole 2,between it and inner surfaces of the attachment hole 2.

Because the seal member 3 is made of elastic material such as rubber,synthetic resin, metal or a braid of glass fibers or carbon fibers, whenan external force resulting from an earthquake or the like is applied tothe concrete products A, B joined, the seal member 3 located at theirjoining points exerts its flexibility, providing a high follow-upability to and high absorbing properties of the external force. Thus,unlike the conventional joining method in which the adhesive S is usedto join the concrete products A, B, the joining points of the concreteproducts A, B do not break under stresses, leading to improvedearthquake resistant properties. In addition, because the protrudingportion 3a provided at the end of the seal member 3 is inserted andlocked in the attachment hole 2 in such a manner as to providewatertightness, leakage of liquid can be reliably prevented, leading toimproved water cutoff properties.

Further, in the present embodiment, in order to attach the rear end ofthe seal member 3 to the joining face 1 of the product B, as is the casewith the attachment of its front end, the substantially semi-circular insection protruding portion 3a provided at the rear end of the sealmember 3 is inserted through the opening 2a provided circular in frontview in the joining face 1 of the product B into the attachment hole 2while bringing the closing press contact portion 3c located rearwardlyof the protruding portion 3a into press contact with inner surfaces ofthe opening 2a and attaining an airtight condition inside the attachmenthole 2, followed by filling the grout 6 into the space K defined betweeninner surfaces of the attachment hole 2 and the protruding portion 3aand setting the same. The means of attaching the seal member 3 to theconcrete product B, however, are not limited to the above and include anot-shown anchor of appropriate form which is embedded for the mentionedpurpose in the product B and other appropriate fixing means such asadhesion, screwing or the like.

FIGS. 6 and 7 show a joining structure for concrete products accordingto a second embodiment of the present invention.

In this embodiment, of the concrete products A and B in the form of boxculverts b, b to be joined together, one concrete product A has anattachment surface 1A formed at a desired angle of θ₁ at the side of andrelative to the joining face 1. Likewise, the other concrete product Bto be joined to the one concrete product A has an attachment surface 1Bformed at a desired angle of θ₂ at the side of and relative to itsjoining face 1, to which attachment surface 1B is attached the rear endof the seal member 3.

The opening 2a is formed substantially circular in front view at leastin the attachment surface 1A of the one concrete product A, and theattachment hole 2 is provided at a depth of the opening 2a.

As the desired angle θ₁, θ₂ of the attachment surface 1A, 1B relative tothe joining face 1, 1, an appropriate one is selected which facilitatesthe joining operation of the concrete products A, B by means of the sealmember 3, serves to prevent the protruding portion 3a of the seal member3 from coming off the attachment hole 2 after completion of the joiningof the concrete products A, B, and serves to achieve sufficient watercutoff properties. The angle in the present embodiment is mostpreferably in the range, for example, of 30° to 60°.

Designated 3d₁ is an introduction port for the grout 6, which opens atone end to the outside at the rear of the closing press contact portion3c and extends in section slantingly axially of the seal member 3 tocommunicate at the other end to the introduction passage 7. The grout 6is filled into the introduction passage 7 through the introduction port3d₁.

Designated 3d₂ is a filler checking hole for checking the filledcondition of the grout 6, which opens at one end to the outside at therear of the closing press contact portion 3c and extends in sectionslantingly axially of the seal member 3 to communicate at the other endto the introduction passage 7. The filler checking hole 3d₂ may beprovided in plural as desired. The grout 6 is checked from outsidethrough the filler checking hole 3d₂ which is there-after closed with anot-shown pin pressed therein.

To join together the concrete products A, B in the form of box culvertsb, b, the protruding portion 3a provided at one end of the seal member3--which is attached to the attachment surface 1B of one concreteproduct B formed at the desired angle θ₂ relative to the joining face1--is first inserted through the opening 2a in the attachment surface 1Aof the other concrete product A formed at the desired angle θ₁ relativeto the joining face 1 into the attachment hole 2. The closing presscontact portion 3c provided rearwardly of the protruding portion 3a thencomes into press contact with inner surfaces of the opening 2a to makethe interior of the attachment hole 2 airtight. The grout 6 such as anon-shrinkable cement mortar is then filled from outside through theintroduction passage between inner surfaces of the attachment hole 2 andthe protruding portion 3a into the space K defined between innersurfaces of the attachment hole 2 and the protruding portion 3a, and isset to fix the protruding portion 3a inside the attachment hole 2 andjoin the concrete products A, B together by means of the seal member 3.

Because in this embodiment the opening 2a continuous to the attachmenthole 2 is provided in the attachment surface 1A, 1B formed at thedesired angle θ₁, θ₂ in the range, for example, of 30° to 60° at theside of and relative to the joining face 1, 1 of the concrete product A,B, the insertion and mounting of the protruding portion 3a of the sealmember 3 in the attachment hole 2 is readily effected to lead to an easyand reliable joining of the products A, B, and the opening 2a and theprotruding portion 3a are prevented from being aligned in a straightline to secure the protruding portion 3a inside the opening 2a to attainsufficient water cutoff properties.

In this second embodiment, as described above, the attachment surface1A, 1B of the concrete product A, B to be joined together is provided atthe desired angle θ₁, θ₂ at the side of the joining face 1, 1; theopening 2a is formed substantially circular in front view in theattachment surface 1A, 1B and the protruding portion 3a at the front endof the seal member 3 is inserted through the opening 2a into theattachment hole 2 located at a depth of the opening 2a; the grout 6 isfilled into the space K in the attachment hole 2 through theintroduction port 3d₁ provided in the seal member 3 so as to open at oneend to the outside at the rear of the closing press contact portion 3cand at the other end communicate to the introduction passage 7; and anappropriate number of the filler checking holes 3d₂ are provided in theseal member 3 so as to open at one end to the outside at the rear of theclosing contact portion 3c and at the other end communicate to theintroduction passage 7, through which the filled condition of the grout6 in the introduction passage 7 is checked during its filling and whichare, after completion of the filling of the grout 6, closed with thenot-shown pins pressed into their one end opening to the outside to setthe grout 6 and join the products A, B together by means of the sealmember 3 located therebetween. The position where to set the attachmentsurface 1A, 1B, however, is not limited to the side of the opposedjoining faces of the concrete products A, B, and the attachment surface1A, 1B may be provided externally on the concrete products A, B at thedesired angle θ₁, θ₂. In this case, the insertion of the protrudingportion 3a through the opening 2a--which is provided substantiallycircular in front view in the above attachment surface 1A, 1B--into theattachment hole 2 located at a depth of the opening 2a can be effectedwhile checking from outside its being inserted. The grout 6 isthereafter filled into the space K as in the preceding embodiment andset to join the concrete products A, B together by means of the sealmember 3 provided externally thereon.

FIG. 8 shows a third embodiment of the present invention. In thisembodiment, the closing press contact portion 3c of the seal member 3located rearwardly of the protruding portion 3a has a plurality oflocking tongues 3c₂ formed on at least one of its upper and lowersurfaces, in the illustrated example on both its upper and lowersurfaces, the plurality of locking tongues 3c₂ coming into press contactwith inner surfaces of the opening 2a on inserting the protrudingportion 3a of the seal member 3 through the opening 2a into theattachment hole 2, so that the grout 6 is filled into the space Kdefined between inner surfaces of the attachment hole 2 and theprotruding portion 3a under a satisfactory airtight condition achievedinside the attachment hole 2 and set to join together the concreteproducts A, B by means of the seal member 3.

FIGS. 9 and 10 show a fourth embodiment of the present invention.

The present invention is in this embodiment applied to joining togetherconcrete products A, B in the form of side channels or U-shaped channelsU, U in place of the concrete products A, B in the form of box culverts1, 1 as in the first embodiment. The concrete products A, B in thisembodiment include respective attachment surfaces 1A, 1B formed at thedesired angles θ₁, θ₂ relative to their joining faces 1, 1, andattachment holes 2, 2 having side openings 2c, 2c at their both left andright ends.

The seal member 3 is inserted through one of the side openings 2c,2c--which is selected in consideration of the site conditions, laidcondition of the side channels and the like--into the attachment hole 2from the direction Z intersecting the joining direction X of theconcrete products A, B.

Thus, because the protruding portion 3a of the seal member 3 can beinserted into the attachment hole 2 from not only the joining directionX of the concrete products A, B, but also from the direction Zvertically intersecting the joining direction X or the direction Yhorizontally intersecting the joining direction X, the insertionoperation of the seal member 3 is facilitated. The grout 6 is thenfilled into the space K defined between the inner surfaces of theattachment hole 2 and the protruding portion 3a and set to fix theprotruding portion 3a of the seal member 3 in position. In this case,after insertion of the protruding portion 3a into the attachment hole 2,one of the side openings 2c, 2c of the attachment hole 2 is filled andclosed with a filler such as rubber, synthetic resin or cement mortar toachieve an airtight condition inside the space K, so that the grout 6can be filled into the space K and set.

FIG. 11 shows a fifth embodiment of the present invention.

In this embodiment, the protruding portion 3a of enlarged diameterprovided at the front end of the elastic material-made seal member 3,unlike the preceding examples in which it has a semi-circular section,has a regular circular section smaller than that of the attachment hole2. Further, the seal member 3 is internally provided with anintroduction passage 7' which extends in a width direction thereof andcommunicates to the attachment hole 2. The grout 6 is filled throughthis introduction passage 7' into the space K defined between the innersurfaces of the attachment hole 2 and the protruding portion 3a and setto fix the protruding portion 3a of the seal member 3 in the attachmenthole 2 and join the concrete products A and B together by means of theseal member 3.

In the illustrated example, one introduction passage 7' is providedextending in the width direction of the seal member 3 and is at thefront end provided with branches opening to the upper and lower surfacesof the seal member 3 and putting the same in communication with theattachment hole 2. This, however, is an example, and the introductionpassage 7' is not limited in number to one and may be provided inplural. In addition, the front end of the introduction passage 7' may beextended to either one of the upper and lower surfaces of the sealmember 3 for the filling of the grout 6 into the space K.

Incidentally, also in the third embodiment shown in FIG. 8 and the fifthembodiment shown in FIG. 11, as in the second embodiment shown in FIGS.6 and 7, the seal member 3 may be provided with introduction ports 3d₁for the grout 6 and an appropriate number of filler checking holes 3d₂,so that the filling of the grout 6 into the space K between innersurfaces of the attachment hole 2 and the protruding portion 3a of theinserted seal member 3 can be effected while checking the grout 6 beingfilled into the space K.

INDUSTRIAL APPLICABILITY OF THE INVENTION

As described hereinabove, according to the present invention, theprotruding portion at the front end of the elastic-material made sealmember attached to one concrete product is inserted into the attachmenthole of enlarged diameter provided at a depth of the opening formed inthe other concrete product, while bringing the closing press contactportion provided rearwardly of the protruding portion into press contactwith inner surfaces of the opening to achieve an airtight condition inthe attachment hole. The grout is then filled into the space definedbetween the inner surfaces of the attachment hole and the insertedprotruding portion and set. The above permits even an unskilled personto securely join concrete products together with a simple handlingoperation. Further, because the protruding portion is fixed in theattachment hole by the grout filled in and set in the spcace definedbetween inner surfaces of the attachment hole and the protrudingportion, the concrete products are structurally firmly joined togetherand have a rigid connectivity, and are excellent in earthquake resistantproperties and water cutoff properties. Further, the present inventioncontributes to a simple production and design, leading to a reduction inconstruction costs and material costs.

What is claimed is:
 1. A joining method for pre-formed concrete productscomprising the steps of:inserting a protruding portion located at afront end of a seal member which is formed of elastic material and whichis attached at a rear end to a joining face of a first concrete product,through an opening formed in a joining face of a second concrete productwhich is placed in direct abutting engagement with said first concreteproduct, and into an attachment hole of enlarged diameter provided at anend of said opening; bringing a closing press contact portion providedrearwardly of said protruding portion, into press contact with innersurfaces of said opening in a manner which renders an interior of saidattachment hole airtight, said closing press contact portion having athickness which increases away from said protruding portion at a rategreater than a rate at which a width of opening increase; and fillinggrout into a space defined between inner surfaces of said attachmenthole and said closing press contact portion and said protruding portioninserted into said attachment hole, and setting said grout therein tojoin said first and said second concrete products together by means ofsaid seal member.
 2. The joining method for concrete products accordingto claim 1, wherein said step of filling grout comprises filling saidgrout through and into said space which serves as an introductionpassage for said grout, and which is defined between the inner surfacesof said attachment hole and said protruding portion provided at thefront end of said seal member inserted into said attachment hole.
 3. Thejoining method for concrete products according to claim 1, wherein saidstep of filling grout comprises filling said grout through anintroduction passage in communication with said attachment hole, whichis provided internally of said seal member whose protruding portion atthe front end is inserted into said attachment hole, into said spacedefined between the inner surfaces of said attachment hole and saidprotruding portion inserted into said attachment hole.
 4. A joiningmethod for pre-formed concrete products, one of the concrete productsincludes a first attachment surface formed at a desired angle on ajoining face thereof, and the other of the concrete products includes asecond attachment surface formed at a desired angle on a joining facethereof, an opening formed in said second attachment surface and anattachment hole of enlarged diameter formed at a bottom of said opening,said method comprising the steps of:inserting a protruding portion whichis provided at a front end of a seal member that is made of elasticmaterial, and that is attached at a rear end of the seal member to saidfirst attachment surface, through said opening formed in said secondattachment surface into said attachment hole; bringing a closing presscontact portion provided rearwardly of said protruding portion intopress contact with inner surfaces of said opening in a manner whichrenders an interior of said attachment hole airtight, said closing presscontact portion having a thickness which increases away from saidprotruding portion at a rate greater than a rate at which a width ofopening, increases; and filling grout into a space defined between innersurfaces of said attachment hole and said closing press contact portionand said protruding portion inserted into said attachment hole andsetting said grout there to join said one and said the other concreteproducts together by means of said seal member.
 5. The joining methodfor concrete products according to claim 4, wherein said step ofinserting comprises inserting said protruding portion provided at thefront end of said seal member from a direction substantiallyperpendicular to a joining direction of said concrete products into saidattachment hole, and said step of filling grout comprises filling saidgrout, after completion of the insertion of said protruding portion intosaid attachment hole, from a direction substantially perpendicular tosaid joining direction of said concrete products into said space definedbetween the inner surfaces of said attachment hole and said protrudingportion.
 6. The joining method for concrete products according to claim4, wherein said seal member with said protruding portion formed at thefront end which is inserted and fixed in said attachment hole providedat the depth of said opening formed in said attachment surface isprovided at an outer side of the opposed concrete products.
 7. Thejoining method for concrete products according to claim 4, wherein saidseal member with said protruding portion formed at the front end whichis inserted and fixed in said attachment hole provided at the depth ofsaid opening formed in said attachment surface is provided at an innerside of the opposed concrete products.
 8. A joining structure forconcrete products comprising:first and second opposed pre-formedconcrete products each with a joining face; a seal member of elasticmaterial attached to said joining face of said first concrete productand including a protruding portion at a front end thereof and a closingpress contact portion provided rearwardly of said protruding portion;and an opening formed in said joining face of said second concreteproduct, said opening having an attachment hole of enlarged diameterprovided at a bottom of said opening, said protruding portion having athickness which increases away from said closing press contact portionat a rate greater than a rate at which a width of opening, wherein saidprotruding portion of said seal member is inserted through said openinginto said attachment hole, said closing press contact portion is broughtinto press contact with inner surfaces of said opening to render aninterior of said attachment hole airtight, and wherein grout is filledinto a space defined between inner surfaces of said attachment hole andsaid closing press contact portion and said protruding portion insertedinto said attachment hole and set to join said first and second concreteproducts together by means of said seal member.
 9. The joining structurefor concrete products according to claim 8, wherein said opening istapered toward said attachment hole of enlarged diameter provided at thedepth of said opening, and a narrow part is formed at a boundary betweensaid attachment hole and said opening.
 10. The joining structure forconcrete products according to claim 8, wherein said closing presscontact portion is formed on a tapered inclined portion of said sealmember which is of such height as to be capable of comming into presscontact with the inner surfaces of said opening.
 11. The joiningstructure for concrete products according to claim 8, wherein saidclosing press contact portion has locking tongues formed in a serratedmanner on at least one of upper and lower surfaces thereof, whichtongues are capable of coming into press contact with the inner surfacesof said opening.
 12. A joining structure for concrete productscomprising:first and second opposed pre-formed concrete products eachwith a joining face, said first concrete product including a firstattachment surface formed at a desired angle on said joining facethereof, said second concrete product including a second attachmentsurface formed at a desired angle on said joining face thereof, anopening formed in a tapered manner in section in said second attachmentsurface, an attachment hole of enlarged diameter provided at an end ofand continuous to said opening; a seal member of elastic material havinga rear end attached to said first attachment surface of said firstconcrete product, said seal member including a protruding portion at afront end thereof which is larger in diameter than a minimum dimensionbetween inner surfaces of said opening and which is insertable into saidattachment hole, and a closing press contact portion formed rearwardlyof said protruding portion which elastically comes into press contactwith the inner surfaces of said opening, said closing press contactportion having a thickness which increases away from said protrudingportion at a rate greater than a rate at which a width of openingincreases, wherein said protruding portion of said seal member isinserted into said attachment hole to render the interior of saidattachment hole airtight, and wherein grout is then filled into a spacedefined between inner surfaces of said attachment hole and said sealmember inserted into said attachment hole and is set to join said firstand second concrete products together by means of said seal member. 13.The joining structure for concrete products according to claim 9,wherein said first concrete product further has an opening formed insaid respective first attachment surface and an attachment hole at theend of said respective opening, and said seal member is at said rear endprovided with a first closing press contact portion and a firstprotruding portion, wherein after positioning said protruding portionsand said closing press contact portions of opposite ends of said sealmember in said respective attachment holes and said respective openingscontinuous to said attachment holes of said first and second concreteproducts, grout is filled into spaces defined between the inner surfacesof said attachment holes and said closing press contact portion and saidprotruding portions inserted into said respective attachment holes andis set to join said first and second concrete products together by meansof said seal member.